2003 VW GTI 1.8T 20th Annie. / Need help with parts

The following are the things that I have in my car:

Cold-Air Intake
Full Exhaust System / Muffler
Bypass For Catylac Converter

I've been wanting to put a Performance Chip on it but I have heard many rumors that if i do that, they will void my VW Warranty... Does anybody know if this is true? If it is then what else can i put in my car to increase hp? I have 1000$ more or less to spend on something but I want to find something that ill give me that bang for the buck.

Hello, I am not a lawyer, but I want you to put yourself in the service managers shoes for a few minutes
Customer arrives in atow truck his with dead, VW car. on the hook. SOB SOB My transmission is dead or my motor went bang. Heres my warrantee PLEASE FIX IT FREE. They are busy. Customer goes home.
A day later the certified mechanic puts it on a hoist. He does a quick walk around and takes a few notes. Here is where the trouble starts. This mechanic is factory certified to perform warrantee work. The first thing he notes is the customer has a flash set of non factory approved tires and wheels. This does not neccesarily void the warrantee, just may be a safety violation and will be noted. Then the car is raised, and a quick but thorough inspection underneath is done, including brake rotor and pad condition. Any competent shop does this for your safety. MMMMM there is a very illegal convertor bypass . OUCH Now he lowers the car , and pulls all the information from the computer. Voila, Engine peak RPM , Speed prior to air bag deployment, serial number of the installed chip, and a lot of other items come up. He takes a hard copy and brings it to you the service manager. Then goes on to the next car.

If they want to be really sticky and you want to argue a call to your states motor vehicle inspection is horribly expensive for you. He knows that. Further he knows fully well that your lawyer will cost you as much as the work, and
you will wind up paying both bills. He makes a lot more money with a legitimate claim denial. He will probably say sorry,
NO WARRANTEE, but we can fix it for lots of dollars. Allan